scholarly journals Concrete Compressive Strength under Changing Environmental Conditions during Placement Processes

Materials ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 4577 ◽  
Author(s):  
Andrzej Ambroziak ◽  
Patryk Ziolkowski
Keyword(s):  
Compressive Strength ◽  
Technological Process ◽  
Daily Temperature ◽  
Hardened Concrete ◽  
Concrete Compressive Strength ◽  
Concrete Mix Design ◽  
Temperature And Precipitation ◽  
Concrete Production ◽  
Concrete Mix ◽  
Limiting Behaviour

The technological process of concrete production consists of several parts, including concrete mix design, concrete mix production, transportation of fresh concrete mix to a construction site, placement in concrete framework, and curing. Proper execution of these steps provides good quality concrete. Some factors can disturb the technological process, mainly temperature and excessive precipitation. Changing daily temperature and rainfall during fabrication, transportation, and placement can shape not only the properties of the concrete mix but also the compressive strength of hardened concrete. In this paper, we tried to answer the question of how temperature and precipitation affect concrete production. The scope of this study was to determine the change of compressive strength of the hardened concrete in a specific period for selected concrete mix recipes, taking into account changing daily temperature and precipitation magnitude. The investigated concrete mixes concrete compressive strength beyond that of the concrete grade, termed “concrete superstrength”. This concrete post limiting behaviour of concrete is also discussed.

scholarly journals PEMANFAATAN LIMBAH CANGKANG KERANG HIJAU DENGAN VARIASI SUHU PEMBAKARAN SEBAGAI BAHAN PENGGANTI SEBAGIAN SEMEN PADA PEMBUATAN BETON

2020 ◽  
Vol 14 (1) ◽  
Author(s):  
Julia Widia Nika ◽  
Anisah Anisah ◽  
Rosmawita Saleh
Keyword(s):  
Compressive Strength ◽  
Chemical Substance ◽  
Mix Design ◽  
Partial Replacement ◽  
Concrete Compressive Strength ◽  
Mussel Shell ◽  
Concrete Mix Design ◽  
Concrete Mix ◽  
Shell Waste ◽  
And Control

This research aims to utilize green mussel shell waste as a partial replacement for cement by establishing the best temperature that should be used to obtain the chemical substance if the sehell ashes to optimize the chemical substance for replacement of cement. This research replaces 10% of total weight cement with shell ash which has been combusted with a temperature of 700 ° C, 800 ° C and 900 ° C and control concrete. The compressive strength of the concrete plan is 20 MPa. Concrete mix design is 1:2:3. The results of this study indicate with subtitutes 10% semen with green shell ash with temperature 700 ° C, 800 ° C and 900 ° C is 20,53MPa; 16,76 MPa and 19,74 MPa and for control concrete has compressive strength 20,18 MPa. The maximum concrete compressive strength was obtained on the concrete of green shell ash with a combustion temperature of 700 ° C which is 20.53 MPa. In the concrete the green shells ash with a burning temperature above 700 ° C experience a decrease in compressive strength and cannot meet the compressive strength of the plan.

scholarly journals Study of the Influence of an Air-Entraining Agent on the Rheology of Motars

2018 ◽  
Vol 149 ◽  
pp. 01054
Author(s):  
Nadia Tebbal ◽  
Zine El Abidine Rahmouni ◽  
Lamis Rabiaa Chadi
Keyword(s):  
Compressive Strength ◽  
Rheological Properties ◽  
Fresh Concrete ◽  
Experimental Studies ◽  
Air Entrainment ◽  
Mix Design ◽  
Hardened Concrete ◽  
Concrete Mix Design ◽  
Concrete Mix ◽  
Mixing Water

The objective of this study is to analyze the effect of the air entrainment on the fresh rheological properties as well as on the compressive mechanical resistances of the mortars. The hardened concrete contains a certain amount of randomly spread air, coming either from a drive during kneading or from the evaporation of the mixing water. The air quantity is in the order of 20 l / m3, ie 2% of the volume. However, the presence of a large volume of air bubbles causes the mechanical resistances to fall in compression. On the other hand, the use of air entrainment could improve the rheological properties of fresh concrete. Experimental studies have been carried out to study the effect of air entrainment on compressive strength, density and ingredients of fresh concrete mix. During all the study, water cement ratio (w/c) was maintained constant at 0.5. The results have shown substantial decreasing in water and mortar density followed with decreasing in compressive strength of mortar. The results of this study has given more promising to use it as a guide for mortar mix design to choose the most appropriate concrete mix design economically.

scholarly journals Model-Based Adaptive Machine Learning Approach in Concrete Mix Design

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1661
Author(s):  
Patryk Ziolkowski ◽  
Maciej Niedostatkiewicz ◽  
Shao-Bo Kang
Keyword(s):  
Machine Learning ◽  
Compressive Strength ◽  
Concrete Strength ◽  
Design Methods ◽  
Mix Design ◽  
Engineering Practice ◽  
Concrete Compressive Strength ◽  
Concrete Technology ◽  
Concrete Mix Design ◽  
Concrete Mix

Concrete mix design is one of the most critical issues in concrete technology. This process aims to create a concrete mix which helps deliver concrete with desired features and quality. Contemporary requirements for concrete concern not only its structural properties, but also increasingly its production process and environmental friendliness, forcing concrete producers to use both chemically and technologically complex concrete mixtures. The concrete mix design methods currently used in engineering practice are joint analytical and laboratory procedures derived from the Three Equation Method and do not perform well enough for the needs of modern concrete technology. This often causes difficulties in predicting the final properties of the designed mix and leads to precautionary oversizing of concrete properties for fear of not providing the required parameters. A new approach that would make it possible to predict the newly designed concrete mix properties is highly desirable. The answer to this challenge can be methods based on machine learning, which have been intensively developed in recent years, especially in predicting concrete compressive strength. Machine learning-based methods have been more or less successful in predicting concrete compressive strength, but they do not reflect well the variability that characterises the currently used concrete mixes. A new adaptive solution that allows estimating concrete compressive strength on the basis of the concrete mix main ingredient composition by including two observations for a given batch of concrete is proposed herein. In presented study, a machine learning model was built with a deep neural network architecture, trained on an extensive database of concrete recipes, and translated into a mathematical formula. Testing on four concrete mix recipes was performed, which were calculated according to contemporary design methods (Bolomey and Fuller method), and a comparative analysis was conducted. It was found out that the new algorithm performs significantly better than that without adaptive features trained on the same dataset. The presented algorithm can be used as a concrete strength checking tool for the concrete mix design process.

scholarly journals The effect of the pre-wetting of expanded clay aggregate on the freeze-thaw resistance of the expanded clay aggregate concrete

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Michał Piotr Musiał ◽  
Filip Grzymski ◽  
Tomasz Trapko
Keyword(s):  
Compressive Strength ◽  
Moisture Content ◽  
Concrete Compressive Strength ◽  
Aggregate Concrete ◽  
Freeze Thaw ◽  
Concrete Mix Design ◽  
In Series ◽  
Resistance Criterion ◽  
Mixing Water ◽  
Nominal Amount

AbstractThis paper presents experimental research on expanded clay aggregate concrete. The aim of the investigations was to determine if the pre-wetting of expanded clay aggregate has an effect on the freeze-thaw durability of the expanded clay aggregate concrete. Five concrete series based on the same concrete mix design were made and tested. The degree of pre-wetting of the aggregate was varied: dry aggregate was used in the first series, aggregate with a moisture content of 10% was used in series IA and IB and aggregate with a moisture content of 25% was used in series IIA and IIB. Also the approach to the production process was varied: in series A the water contained in the aggregate was taken into account in the global water-cement ratio (consequently a reduced amount of water was added to the mix), whereas in series B the nominal amount of water was added to the mix (as in the case of dry aggregate). The freeze-thaw resistance criterion was based on the assessment of the decrease of compressive strength and increase in weight loss after exposure to freeze-thaw cycles. The expanded clay aggregate concrete's strength and mass decrements caused by freeze-thaw cycling were used as the measure of its freeze-thaw resistance. The investigations have shown that the pre-wetting of expanded clay aggregate has an effect on the freeze-thaw durability of the expanded clay aggregate concrete. The differences of concrete compressive strength decrease related to freeze-thaw durability may be 2 to 5 times greater when inadequate method of calculating mixing water for concrete is used.

scholarly journals Developing Sustainable Concrete Compaction using a Proposed Multi-vibration Technique

2020 ◽  
Vol 13 (1) ◽  
pp. 45-53
Author(s):  
Sajid Kamil Zemam
Keyword(s):  
Compressive Strength ◽  
Vibration Mode ◽  
Sustainable Construction ◽  
Experimental Program ◽  
Specific Method ◽  
Concrete Compressive Strength ◽  
Time Duration ◽  
Construction Technique ◽  
Vibration Technique ◽  
Concrete Production

This study seeks to develop a sustainable construction technique based on the introduction of a specific method for improving concrete compressive strength through a proposed multi-vibration compaction method. An experimental program is performed to evaluate the effect of the proposed compaction technique on fresh silica fume concrete undergoing the initial setting. Multi-vibration intends to minimize concrete production cost because it upgrades the compressive strength of the same materials with better utilization of the vibration energy required for compaction. The collected experimental data presented assign relationships among vibration duration, vibration cycles or phases, and compressive strength upgrading of single vibrated, revibrated, and multi-vibrated specimens for analysis and discussion. This study shows that multi-vibration phases, rather than single vibration or revibration techniques, are powerful techniques for improving concrete compressive strength. The results indicated that the existence of an optimum multi-vibration mode was dominated by phase number and vibration duration and confirm the reliability vibration overall time duration recommended by ACI 309 which relates to a single vibration time limit to be considered in the case of multi vibration technique. Multi-vibration Mode 8 (subjected to three vibration phases 10, 20, and 30 sec ) has the best effect for the considered mixtures among the specific vibration modes. The maximum improvement ratio is 1.25, which is associated with the plastic mixture.   

scholarly journals Artificial Neural Network Estimation of the Effect of Varying Curing Conditions and Cement Type on Hardened Concrete Properties

Buildings ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 10 ◽  
Author(s):  
Gökhan Kaplan ◽  
Hasbi Yaprak ◽  
Selçuk Memiş ◽  
Abdoslam Alnkaa
Keyword(s):  
Compressive Strength ◽  
Portland Cement ◽  
Limestone Powder ◽  
Mineral Admixtures ◽  
Hardened Concrete ◽  
Slag Cement ◽  
Curing Conditions ◽  
Concrete Properties ◽  
Concrete Production ◽  
Artificial Neural

The use of mineral admixtures and industrial waste as a replacement for Portland cement is recognized widely for its energy efficiency along with reduced CO2 emissions. The use of materials such as fly ash, blast-furnace slag or limestone powder in concrete production makes this process a sustainable one. This study explored a number of hardened concrete properties, such as compressive strength, ultrasonic pulse velocity, dynamic elasticity modulus, water absorption and depth of penetration under varying curing conditions having produced concrete samples using Portland cement (PC), slag cement (SC) and limestone cement (LC). The samples were produced at 0.63 and 0.70 w/c (water/cement) ratios. Hardened concrete samples were then cured under three conditions, namely standard (W), open air (A) and sealed plastic bag (B). Although it was found that the early-age strength of slag cement was lower, it was improved significantly on 90th day. In terms of the effect of curing conditions on compressive strength, cure W offered the highest compressive strength, as expected, while cure A offered slightly lower compressive strength levels. An increase in the w/c ratio was found to have a negative impact on pozzolanic reactions, which resulted in poor hardened concrete properties. Furthermore, carbonation effect was found to have positive effects on some of the concrete properties, and it was observed to have improved the depth of water penetration. Moreover, it was possible to estimate the compressive strength with high precision using artificial neural networks (ANN). The values of the slopes of the regression lines for training, validating and testing datasets were 0.9881, 0.9885 and 0.9776, respectively. This indicates the high accuracy of the developed model as well as a good correlation between the predicted compressive strength values and the experimental (measured) ones.

scholarly journals The Use of Fragmented, Worn-Out Car Side Windows as an Aggregate for Cementitious Composites

Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1467 ◽  
Author(s):  
Maciej Szeląg ◽  
Bartosz Zegardło ◽  
Wojciech Andrzejuk
Keyword(s):  
Water Resistance ◽  
Microscopic Analysis ◽  
Hardened Concrete ◽  
Side Window ◽  
Recycled Glass ◽  
Air Content ◽  
Concrete Production ◽  
Concrete Mix ◽  
Glass Aggregate ◽  
Composite Samples

The paper describes a new model of concrete production, which contains a glass cullet. A worn-out car side window have been used for the production of recycled glass aggregate (RGA) and its properties were examined. The RGA was used in concrete as a 50% and 100% mass substitute of the traditional aggregate. Basic tests of fresh concrete mix and hardened concrete were carried out. The consistency, the air content in the concrete mix, the density of hardened concrete, water absorption, water resistance, frost resistance, and the compressive strength (after 9, 28, and 90 days) were evaluated. Composite samples were also subjected to microscopic analysis. The results showed that the RGA can be recommended as an aggregate for concretes, and the features of the RGA concrete are more favorable than those of traditional concrete. The microscopic analyses allowed us to identify the reasons for improving the properties of the RGA composites.

scholarly journals The Effect of Adding Slag, Achieved from Wastewater Sludge Incineration in Fluidized-Bed Furnace, on the Quality of Concrete

2019 ◽  
Vol 1 (1) ◽  
pp. 244-250
Author(s):  
Alina Pietrzak
Keyword(s):  
Compressive Strength ◽  
Frost Resistance ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Wastewater Sludge ◽  
Hardened Concrete ◽  
Sludge Incineration ◽  
Concrete Mix ◽  
Compressive Strength Of Concrete

Abstract Due to a constant increase in generating the amount of sewage waste it is necessary to find an alternative method of its use or disposal. One of such methods can be utilization of sewage sludge in construction materials industry, particularly in concrete technology and other materials based on cement. It allows using waste materials as a passive additive (filler) or also as an active additive (replacement of part of bonding material). The article aims at presenting the analysis of the effect of adding slag, achieved from wastewater sludge incineration in sewage treatment plant, on properties and quality of concrete mix and hardened concrete. Using an experimental method, the researcher designed the composition of the control concrete mix, which was then modified by means of slag. For all concrete mixtures determined – air content with the use of pressure method and consistency measured by the use of concrete slump test. For all concrete series the following tests were conducted: compressive strength of concrete after 7, 28 and 56 days of maturing, frost resistance for 100 cycles of freezing and thawing, water absorption. The use of slag, ground once in the disintegrator, causes a decrease of in compressive strength of concrete samples in relation to the control concrete series as well as bigger decrease in compressive strength after frost resistance test.

scholarly journals PROPERTIES OF CEMENT PASTE AND CONCRETE CONTAINING CALCIUM CARBIDE WASTE AS ADDITIVE

2016 ◽  
Vol 36 (1) ◽  
pp. 26-31
Author(s):  
EN Ogork ◽  
TS Ibrahim
Keyword(s):  
Compressive Strength ◽  
Cement Paste ◽  
Setting Time ◽  
Drying Shrinkage ◽  
Calcium Carbide ◽  
Linear Shrinkage ◽  
Hardened Concrete ◽  
Concrete Compressive Strength ◽  
Initial Setting Time ◽  
Standard Procedures

This paper assessed the effect of calcium carbide waste (CCW) as additive on the properties of cement paste and concrete. The CCW used was sourced from a local panel beating workshop. It was sundried and sieved through a 75 µm sieve and characterized by X-Ray Fluorescence (XRF) analytical method. The consistency, setting times and drying linear shrinkage of cement paste with CCW addition of 0, 0.25, 0.5, 0.75 and 1.0 %, respectively by weight of cement were investigated in accordance with standard procedures. The slump values of fresh concrete containing CCW as additive and of 1:2:4 mix ratio and water-cement ratio of 0.5 was determined. A total of sixty numbers of 150 mm cubes of hardened concrete were tested for compressive strength at 1, 3, 7, 28 and 56 days of curing in accordance with standard procedures. The concrete compressive strength was also modeled using Minitab statistical software based on linear regression technique. The results of the investigations showed that CCW was predominantly of calcium oxide (95.69 %) and a combined SiO2, Al2O3 and Fe2O3 content of 3.14 %. The addition of CCW in cement decreased drying shrinkage (100 %), initial setting time (78 %) and final setting time (57 %), but increased consistency (14 %) at 1.0 % CCW content. The addition of CCW in concrete also showed slight increase in slump (6.5 %) and increase in compressive strength with increase in CCW additive up to 0.5 % and decrease in compressive strength with further increase in CCW content. The 28 days compressive strength of concrete with 0.5 % CCW content was 6.4 % more than normal, while that of concrete with 1.0 % CCW content was 14.9 % less than normal. The compressive strength model of CCW-concrete was developed with R2 value of 0.830 and could be used to predict concrete compressive strength. http://dx.doi.org/10.4314/njt.v36i1.4

scholarly journals Effects of Disparate Zones of Sand on the Compressive Strength of Concrete

2021 ◽  
Vol 9 (11) ◽  
pp. 1368-1375
Author(s):  
Suhaib Bakshi
Keyword(s):  
Compressive Strength ◽  
Coarse Aggregate ◽  
Testing Machine ◽  
Concrete Compressive Strength ◽  
Research Papers ◽  
Concrete Material ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Concrete Mix ◽  
Compressive Strength Of Concrete

Abstract: Compressive strength of concrete is the capacity of concrete to bear loads of materials or structure sans breaking or being deformed. Specimen under compression shrinks in size whilst under tension the size elongates. Compressive strength essentially gives concept about the properties of concrete. Compressive strength relies on many aspects such as water-cement ratio, strength of cement, calidad of concrete material. Specimens are tested by compression testing machine after the span of 7 or 28 days of curing. Compressive strength of the concrete is designated by the load on the area of specimen. In this research various proportions of such aggregate mixed in preparing M 30 grade and M 40 grade of Concrete mix and the effect is studied on its compressive strength . Several research papers have been assessed to analyze the compressive strength of concrete and the effect of different zones of sand on compressive strength are discussed in this paper. Keywords: Sand, Gradation, Coarse aggregate, Compressive strength

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